A Clinical Protocol Information System will be designed and implemented so as to support the clinical research and patient care objectives of the Southeastern Cancer Study Group (SEG). Clinical research protocols will be translated into care protocols; use of the latter has already been shown to improve the quality of the SEG's clinical research effort. Institutional investigators will access the patient-specific, visit-specific care protocol encounter forms through institutional-based minicomputers. These institutional-based minicomputers will be linked to a large mainframe computer that centralizes the SEG's data. The mainframe programs will maintain the database, specify management/treatment options available according to the research design, communicate these options and associated data collection requirements to the minicomputer nodes, analyze protocol compliance, and interface the clinical database to the statistical analysis packages utilized by the SEG statistician. The institutional-based minicomputers will drive terminals (data entry and forms output) in the applicable clinics, maintain a data file sufficient to support one day's activity, and communicate with the mainframe once daily. Project goals include: improving the evaluability of the clinical trials, decreasing the frequency of adverse patient events, implementing continuous drug toxicity surveillance, improving the availability of study data, and demonstrating the criteria for computer networks that can impact on the general medical care of the community.